1. Field of the Invention
The invention relates to a device for actuating a release member for a motor and gearbox unit that applies rotary-drive to a tube for winding a closure or solar protection screen. The invention also relates to a closure or solar protection installation including such a device.
The term closure installation is used to cover doors, gates, shutters, and equivalent pieces of equipment.
2. Brief Description of the Related Art
In this kind of installation, it is known to use an electric motor to rotate a tube for winding a panel that constitutes a door or a shutter or a solar protection blind. It is also known, e.g. from EP-A-0 597 780, to provide a drive release member so as to enable operation to be performed manually, in particular for safety reasons, to allow maintenance to be carried out on the installation, or in the event of an electrical power failure. The release member is controlled by a sheathed cable connected to an actuator device. With the help of an actuator device, the user acts on the tension of the cable and thus on the member for releasing the motor and gearbox unit, thereby enabling the motor to be uncoupled from the above-mentioned winding tube.
One such actuator device is described in FR-A-2 647 152. In that application, a release lever is secured to one-fourth of a toothed wheel having the release cable attached thereto. The tension in the cable is then proportional to the extent to which the toothed wheel portion is turned. To turn said portion, the lever is tilted in an operating direction perpendicular to the axis of the wheel. That device also includes a mechanism for locking the toothed wheel. A catch is received in one of the teeth of the wheel. When the wheel is turned through one tooth, the catch disengages from the tooth with which it was engaged and engages in the following tooth. The device is again locked. To unlock it, the user needs to act on a second lever in a direction that is colinear with the previous operating direction. That action has the effect of disengaging the catch from the toothed wheel which then becomes a “free wheel”. Because the actuation directions for locking and unlocking are colinear, there is a major risk of involuntarily action being taken. This risk increases if it is desired to make the device more compact than the device described. It has been found advantageous, in use, and for better control over the force exerted on the cable, for the device to be more compact, ergonomic, and suitable for being gripped firmly in one hand. The solution described in FR-A-2 647 152 also implies locking means that are distinct from the control lever, which is not favorable to reducing overall size.